The policies are stored in the serdef.dat file inside the Symantec Endpoint Protection installation directory.
Default location: - c:\Program Files\Symantec\Symantec Endpoint Protection
Now you said : " Once you remove a sep client, regardless of version 11.2 to 11.6, the policies set from the server (in our case, usb storage devices have been disabled) remains on the computer. "
Questions :
1. How you are removing the SEP?
2. How you are installing it back to the computer?
3. What package are you using?
a. managed
b. unmanaged created from the SEPM
c. Self managed from the SEP installation media or zip file downloaded from http://fileconnect.symantec.com